>>12280360/an/ is such a bizarre board. It's like a third "normal" 4chan users, a third "boop the pupperinos snoot" people, and a third semi professional biologists.
/pol/, /b/, and /v/ are probably some of the lowest iq boards just due to their sheer size and underage userbase. /x/ gets an honorable mention because it's probably the smallest, yet most stupid userbase. I'm in awe of how fucking dumb some of the threads on there are.